A Stat News investigation found that hundreds of patients taking the RA drug died from cardiovascular and pulmonary complications – issues the drug was not usually associated with. According to the investigation, Actemra did not carry warning labels about the possible side effects, unlike many competing RA drugs. Stat said it investigated more than 500,000 side effect reports for RA drugs and “found clear evidence” that the risks of the side effects, such as heart attack or stroke, “were as high or higher for Actemra patients than for patients taking some competing drugs.” The difference Stat stressed is that Actemra, unlike the other RA drugs, does not carry a warning label for those side effects.

Actemra is a humanized interleukin-6 (IL-6) receptor antagonist approved for treatment of adults with moderately to severely active rheumatoid arthritis. It was approved in 2010 and has been prescribed to more than 760,000 patients. The drug was responsible for $1.7 billion in revenue last year, Stat said.

According to Stat’s analyses, the U.S. Food and Drug Administration has received 1,128 death reports of patients who were taking Actemra, However, the federal agency has been unable to determine if the drug was a direct cause of any of the deaths due to a lack of “sophisticated tools,” Stat said.

“Though the agency is charged with monitoring the safety of prescription drugs, it doesn’t verify the side-effect reports it receives. The documents often lack crucial information, and they don’t prove that Actemra was the cause,” Stat said in its report.

Despite that, Stat cites several doctor’s reports that suggest the drug played a major role in the death of patients who received treatment with Actemra. Although the doctors’ comments regarding a suggested link between the deaths and Actemra were included, their identities were not disclosed.

Likewise, Stat cites a number of unnamed experts who reviewed the outlet’s analysis and concluded the FDA must consider adding a warning label to Actemra for heart failure and pancreatitis. The experts Stat cited said a failure to warn consumers “highlights the FDA’s inability to adequately scrutinize the safety of drugs after they have been approved, and to act promptly when potential danger signs appear.”

Vinay Prasad, an oncologist and medical ethicist at the Oregon Health and Science University, told Stat it has become easier to get drugs approved, but the FDA has not been as thorough in conducting “post-marketing surveillance” to ensure a drug is safe and effective. Prasad said the system is broken and “all the financial incentives are lined up to keep it broken.”

In its report Stat compared Actemra to Vioxx, an RA drug that was pulled from the market after it was linked to thousands of deaths from heart attacks. Stat said those problems were not found in the short-term safety tests during clinical trials, but were later discovered after long periods of use.

In May, the FDA approved Actemra for use in patients with Giant Cell Arteritis, a chronic and severe autoimmune condition. This is the first new treatment approved for the condition in more than 50 years, Roche said at the time the FDA greenlit its use. GCA is characterized by inflammation of the arteries in the head, neck and arms. If untreated it can lead to blindness, aortic aneurysm or stroke.

Jeffrey Siegel, senior medical director for rheumatology products at Roche and its subsidiary Genentech (RHHBY), told Stat that the investigation raised “important questions” and said the company tries hard not to “be complacent, and to fully explore these issues.”